Unprocessed cotton brought from the field to a cotton gin for ginning will produce bales of long cotton fibers while the remaining cottonseed will have a residue of lint thereon. Cottonseed processing apparatus has long been used to remove residue lint from cottonseeds which have already been processed in conventional cotton gins to remove the long, staple fibers from the seeds. The lint removed from the cottonseed is one of the salable products procured from the cotton operation.
Lint is typically removed in multiple passes through a cottonseed processing apparatus known as a delinter. The first pass lint yields high quality cellulose, used in manufacturing high quality paper. Lint from the second and third passes is usually sold in blended form, with munitions lint and hygienic cottonballs being common end uses.
It is also desirable to delint seeds to enhance processability for oil extraction. In oil extraction apparatus, lint is a contaminant which detracts from the overall quality of the oil and adds to the maintenance requirements for the oil extraction apparatus.
In the conventional delinter, the lint is continuously removed from seed by subjecting a rotating mass of seed or "seed roll" to a rotating, ganged cylinder of toothed saw blades passing between ribs in a "grate". The lint is "doffed" from the sawteeth by a revolving brush cylinder.
The seed roll is rotated in a "float chamber" where the seed roll is subjected to the saws. Rotation of the seed roll is caused by a rotating paddle wheel "float" in the center of the seed roll.
The density of the see roll in the float chamber is controlled by a feedback controlled paddle wheel roll feeder upstream of the float. The rotating speed of the roll feeder is determined by the amperage required by the saw cylinder motor, such that see roll density is maintained at an optimum level for efficient delinting.
In use, the saw cylinders wear rapidly and require frequency sharpening, so a convenient means of accessing and removing the saw cylinder is required. The conventional delinter thus also includes pivoted gratefall cover pivotally attached to the delinter at the top thereof to enable access to the saw cylinder. The upwardly pivoting gratefall cover requires substantial force to shift it to its open position. In addition, suspension of the gratefall cover above the saw cylinder requires the use of separate saw cylinder shifting arms to lift the saw cylinder from its mounts within the machine and then roll the cylinder outwardly a sufficiently distance to enable access to an overhead crane or cart. This prior art technique of saw cylinder removal is time consuming and inefficient and requires substantial skill on the part of the operator.
It is also known to provide a flat permanent magnet underneath an apron in the seed stream between the roll feeder and the float chamber for the purpose of detaining ferrous "tramp metal". Tramp metal are metallic trash objects such as fasteners that accidentally get mixed into the incoming cottonseeds. While it is extremely infrequent to encounter a trash metal object, it is imperative that some means be provided to prevent such objects from entering the float chamber, where a tramp metal object could cause significant and substantial damage to the saw cylinder. A drawback of the prior art flat magnet tramp metal detainment apparatus i that the tramp metal is not actually separated from the seed flow, and it requires that an operator notice the tramp metal object detained by the magnet on the apron and physically remove it from the seed stream.
The value or price of lint is determined by the percent of foreign matter or "trash" such as broken hulls, kernels, etc. in the lint, and therefore it is also desirable to remove such trash from the lint in the delinter. "Moting", the removal of trash ("motes") from the lint, is accomplished by gravity in a moting chamber, where the heavier or more dense motes fall through an upwardly-flowing airstream created pneumatically to carry away the lint. Typically, makeup air for the moting chamber has been provided through any convenient opening towards the bottom of the apparatus, such as through the motes conveyor chamber directly below the moting chamber.
Another significant drawback to prior art apparatus has been the incidence of fly lint in the delinted seed stream. Fly lint is the lint which escapes with the delinted seeds rather than being removed by the saw cylinders. In the delinted seed stream, fly lint is an unwanted contaminant and it has proved problematic and expensive in the past to control the amount and presence of fly lint in the delinted seeds.
Thus, it can be seen that conventional delinting apparatus currently in use suffers from a number of significant drawbacks. A need presently exists for eliminating these drawbacks, to yield delinting machinery which enables higher efficiency delinting and better quality lint than has previously been obtained.